LITTLE information is available on the metabolism of the red halophilic bacteria, although they represent a most interesting ecological group of organisms and are of some importance in the packing, pickling and curing industries. In a survey of their respiratory activity it was observed that resting cells did not oxidize readily the common carbon compounds usually employed, but actively oxidized glutamic, aspartic and other amino-acids. This observation prompted further study, in the course of which it was discovered that these bacteria possessed an active aspartate–glutamate transaminase system. The results of this work with Pseudomonas salinaria 1 are presented in this preliminary report.